An optical module being one main component in a projector (projection-type display) is generally configured by an illumination optical system including a light source (an illumination unit), and a projection optical system including a light modulation device (a projection optical system). In the field of such a projector, in recent years, a small-sized (palm-sized) light-weight portable projector called micro-projector is becoming popular. In this micro-projector, previously, an LED (Light Emitting Diode) has been mainly used as the light source of an illumination unit.
On the other hand, recently, as a new light source for an illumination unit, a laser is receiving attention. For example, after commercialization of high-power blue and red semiconductor lasers, a green semiconductor laser has also been under development and is almost at the practical-use level. With the background as such, proposed is a projector using single-color lasers (semiconductor lasers) emitting light respectively in three primary colors of red (R), green (G), and blue (B) as the light source of an illumination unit (for example, see Patent Literatures 1 and 2). By using the single-color lasers as the light source, obtained is the projector having a wide range of color reproduction and reduced power consumption.